LulzBot Mini User Manual

2.9. TROUBLESHOOTING
2.9 Troubleshooting
Z Wobble
Undulations in the walls of a print may be due to wobble in the Z axis.
A thorough analysis of the potential causes is given by whosawhatsis
20
in
his article ”Taxonomy of Z axis artifacts in extrusion-based 3d printing”
21
,
however one point of particular interest for users of Slic3r is the wobble
caused by motor steps not matching the pitch of the Z rods thread. This
can be addressed by ensuring the Layer Height setting is a multiple of the
full step length.
The relevant part of the above paper is quoted here:
To avoid Z ribbing, you should always choose a layer height
that is a multiple of your full-step length. To calculate the full-
step length for the screws you’re using, take the pitch of your
screws (I recommend M6, with a pitch of 1mm) and divide by
the number of full-steps per rotation on your motors (usually
200). Microsteps are not reliably accurate enough, so ignore
them for this calculation (though using microstepping will still
make them smoother and quieter). For my recommended M6
screws, this comes out to 5 microns. It’s 4 microns for the M5
screws used by the i3, and 6.25 microns for the M8 screws used
by most other repraps. A layer height of 200 microns (.2mm),
for example, will work with any of these because 200 = 6.25 *
32 = 5 * 40 = 4 * 50.
20
http://goo.gl/iOYoK
21
http://goo.gl/ci9Gz
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LulzBot Mini Specifications

General

Tweezers	Yes
Certification	CE, FCC, WEEE
Product color	Black, Green
Viewing window	No
Maximum print platform temperature	120 °C
Package weight	11330 g
AC input voltage	100/240 V
Power consumption (typical)	150 W
Print technology	-
Printing material	ABS, HIPS, Nylon, PVA, Polycarbonate (PC), Polylactic acid (PLA)
Layer thickness (max)	0.5 mm
Layer thickness (min)	0.05 mm
Maximum build size (WxDxH)	152 x 152 x 158 mm
Filament thickness supported	3 mm
Maximum vertical build speed	275 mm/sec
Printing compartment volume	3.65 L

Weight and Dimensions

Depth	435 mm
Width	340 mm
Height	385 mm
Weight	8550 g